Take a look at the map at World Time Zone to see the difference in hours between your location and your guest(s). Below is a quick guide for common American/Canadian times, but if Europeans (and everyone) could stick to a GMT+/- format, it'd make things easier to work out.

Time Zone

GMT Difference

EST

-5

CST

-6

MST

-7

PST

-8

Alaska

-9

Hawaii

-10

Put down as much information as you want to share; Putting down your interests will help to better match you to people wanting to LP a particular genre.